山西应县护驾岗冲洪积台地地层光释光年龄及其指示意义

OSL age of Hujiagang alluvial-pluvial platform stratum in Yingxian, Shanxi Province and its significance

摘要:

利用细颗粒（4—11μm）石英简单多片再生法（SMAR）光释光测年技术对山西应县护驾岗冲洪积台地地层进行系统测年，研究表明，样品的光释光信号以快组份为主，适合光释光测年。根据年龄数据和深度建立年龄一深度曲线和函数，推算出了剖面的沉积速率。在（距今，后同）66．46ka-33．62ka期间，剖面沉积速率共发生4次变化，沉积速率的变化与同期古里雅冰芯记录的8180变化趋势基本一致，即沉积速率快对应于冷期，沉积速率慢对应于暖期。具体来说，66．46ka一60．23ka，MIS4冷期，沉积速率为0．6055m／ka；60．23ka～47．15ka，MIS3c暖期，沉积速率为0．0382m／ka；47．15ka～42．65ka，MIS3b冷期，沉积速率为0．4512m／ka；37．89ka-33．62ka，MIS3a暖期，沉积速率为0．1986m／ka。综合以上因素得出：气候的变化是研究区66．46ka～33．62ka期间沉积环境变化的主要因素。

Abstract:

We use simplified multiple aliquot regenerative-dose （SMAR） protocol from fine grain quartz （4-11 txm） to systematically dated samples of Hujiagang alluvial-pluvial platform stratum, which is located in Yingxian County, Shanxi Province. OSL signals of these samples dominated by fast component shows that they are suitable for OSL dating. Based on the optical ages obtained and the buried depth of these samples, the age depth curve and function were obtained for dated samples, the accumulation rate for this section is calculated using age-depth function. Deposition rate experienced four changes between 66.46ka and 33.62ka. The change of depositional rate consists with oxygen isotope variations recorded in Guliya ice core, which shows that the depositional rate was fast during cold period, or vice versa. 66.46ka ~ 60. 23ka was cold phase MIS4 and the deposition rate was 0. 6055m/ka; 60.23ka-47.15ka was mild phase MIS3e and the deposition rate was 0. 0382m/ka; 47.15ka-42.65ka was cold phase MIS3b and the deposition rate was 0. 4512 m/ka; 37.89ka-33.62ka was mild phase MIS3a and the deposition rate was 0. 1986m/ka. Based on the analysis above, climate change was the main factor for depositional rate changes between 66.46 and 33.62ka in the studied area.[著者文摘]